Exhaust means for multiple cylinder internal combustion engine

ABSTRACT

The exhaust device for multiple cylinder internal combustion engines of the type where the waste gas pipes lead separately from cylinder to the exhaust sound muffler, the lengths of which is of different magnitude between motor and sound muffler, while individual waste gas pipes inside the sound muffler are prolonged by a certain amount, is characterized in that the waste gas pipes which are prolonged inside the sound muffler have at least one enlargement in their cross-section.

United States Patent 1191' Hiillerl et a1.

1 1 Jan. 9, 1973 [54] EXHAUST MEANS FOR MULTIPLE CYLINDER INTERNALCOMBUSTION ENGINE [75] Inventors: Alois Hiillerl; Karl Landgraf, both ofSchoensee, Germany [73] Assignee: Firma Otto Meinel-CeorgadelM'etallwarenfahrik, Schoensee/Oberpfalz, Germany [22] Filed: Oct. 12,1971 21 Appl. No.: 188,413

[30] Foreign Application Priority Data Oct. 15, 1970 Germany ..G 70 38137.2

[52] US. Cl ..l8l/40, 181/56, 181/35 C, 181/57 [51]" Int.Cl..F01n7/06,F0ln 7/10, FOln7/l8 [58] Field of Search ...-.....181/36 D,40, 46, 56, 35 C,

[56] References Cited UNlTED STATES PATENTS 2,255,579 9/1941 Blanchard2,660,257 11/1953 Bourne et a1. ...18 1/36 D 2,940,249 6/1960 Gospodar..18l/35 C FOREIGN PATENTS OR APPLICATIONS 313,807 6/1929 Great Britain..181/40 Primary Examiner-Robert S. Ward, Jr. Attorney-Robert H Jacob[57] ABSTRACT The exhaust device for multiple cylinder internalcombustion engines of the type where the waste gas pipes lead separatelyfrom cylinder to the exhaust sound muffler, the lengths of which is ofdifferent magnitude between motor and sound muffler, while individualwaste gas pipes inside the sound muffler are prolonged by a certainamount, is characterized inthat the waste gas pipes which are prolongedinside the sound muffler have at least one enlargement in theircross-section.

8 Claims, 4 Drawing Figures PATENTED JAN 9 I975 SHEET 1 BF 3 PATENTEDJAR9 ma 3. 709 .320

SHEET 2 [IF EXHAUST MEANS FOR MULTIPLE CYLINDER INTERNAL COMBUSTIONENGINE BACKGROUND OF THE INVENTION exhaust sound muffler, the lengthsbetween motor and sound muffler are different, while individual wastegas pipes within the muffler are prolonged by a certain amount.

In a known exhaust device of this type, the individual waste gas pipesare prolonged inside the sound muffler by such an amount that togetherthey have the same total length. By these means it is intended toaccomplish that the waste gases enter from the cylinders in the soundmufiler at equal time periods so that no increase occurs in theamplitude of the pressure, by means of which the noises would beamplified and the sound muffler would be mechanically subjected toincreased loads. r

In this known exhaust device, there exists the shortcoming that due toconstruction of the internal combustion engine shorter waste gas pipeswithin the second muffler must be prolonged by a considerable amount inorder to be just as long as the waste gas pipes that are longer due tothe'construction of the internal combustion engine. As a result, thetotal length of the waste gas muffler of the exhaust device becomesexcessively large, which requires a high expenditure of material. Tothis is added a considerable concentration of heat in the prolongedparts of the waste gas pipes which noticeably decrease the life of knownsound mufflers.

SUMMARY OF THE INVENTION- It is an object of the invention to provide anexhaust device of the type mentioned above which does not have theshortcomings mentioned and which excels particularly by smallrequirement of material, a favorable gas discharge and increaseddurability.

Accordingly, the invention provides for the waste gas pipes that areprolonged within the sound muffler that they have at least one expansionor enlargement in their cross-section. As a result of the expansion ofthe cross-section which results in a reduction of the speed of the wastegases, a very advantageous exhaust discharge is obtained and,furthermore, shortening of the waste gas pipes which is likewiseadvantageous for the reasons mentioned. In particular, it is no longernecessary that the waste gas pipes prolonged within the second mufflerextendparallel and at a small distance from one another over the largerpart of their extent and thus heat themselves due to the radiation ofheat, as well as one another, as a result of which the thermal stresswhich is already high is further increased, and thereby the durabilityof the exhaust muffler parts is considerably decreased.

Advantageously the widening of the cross-section may be in the form of abulge. It is particularly advisable in the exhaust device for fourcylinder combustion engines having waste gas pipes that extend inopposite directions inside the sound muffler and are staggered so thatthe bulges extend in opposite directions as related to the longitudinalaxis of the sound muffler. In this manner the space of the sound mufflerthat is available is optimally utilized, so that minimum spacedimensions result. In addition to this, favorable thermal stress isobtained while the bulges of both prolonged waste gas pipes essentiallyincrease the surface as compared to the known form of construction, andthus the heat conduction and radiation are considerably improved.

In regard to conducting the heat away, it is also advantageous that thebulges are of the same shape and volume. It is essential andparticularly advantageous that the bulges be provided with bores for theexit of the waste gases at the gas discharge pipes or at the parts thatare remote from their prolonged parts. In this manner a particularlysatisfactory, even and favorable discharge of the waste gases isobtained. Besides, the waste gases do not flow entirely to the end ofthe prolongations of the waste gas pipes, but they expand and pressalready against the walls ahead of the bulges so that they are radiatedfrom a comparatively large surface. Thus, the thermal stress of theseparts remains within moderate limits whereby the durability isprolonged.

The advantages that may be obtained in accordance with the invention canbe realized at relatively small cost, for example the parts providedwith the bulges of the water gas tubes that are prolonged in the soundmuffler can be formed in that two metal sheets that extendlongitudinally of the sound muffler are maintained as to form ormaterial which rest with their flat sides that define the recessesforming the bulges in the muffler upon one another are, made the same asto form or material.

BRIEF DESCRIPTION OF THE DRAWINGS Further details, features andadvantages of the invention will become apparent from the embodiment ofthe invention illustrated in the drawings in which:

FIG. 1 is a view of one-half of the sound muffler of an exhaust devicewith the waste gas pipes,

FIG. 2 is a section taken along line Il-Il in FIG. 1,

FIG. 3 is a section taken along line IIIIII in FIG. 1, and

FIG. 4 is a schematic plan view of the motor and muffler with the wastegas pipes which connect them.

DESCRIPTION OF THE INVENTION FIG. 1 shows the muffler housing 1 of anexhaust device for multiple cylinder combustion engines. The exhaustpipes 2-5 lead into the muffler housing 1 of a combustion engine whichin this example has four cylinders. Due to the construction or design ofsuch motors, the distances between the connecting locations of the wastegas pipes on the motor to the corresponding connecting locations of thewaste gas pipes on the muffler are of different lengths. The waste gaspipe 2,3 which for these reasons are longer lead by way of conicallyshaped stubs 8, 9 that are provided with gas discharge apertures 6, 7into the sound muffler housing The discharge pipes, 4, 5 which for theaforementioned reasons are shorter, are prolonged by a certain amountinside the sound muffler 1 by means of the pipe members 10, 11. However,the total length of the waste gas pipes 4, 5 that are lengthened bymeans of the pipe members l0, 11 is less than the total length of thewaste gas pipes 2, 3 which are not prolonged. This is schematicallyillustrated in FIG. 4. Each of the pipes 10, 11 comprises an expansionof the cross-section defined by a bulge l2, 13. The bulges 12, 13 areeach of the same shape and volume and extend in opposite directions asrelated to the longitudinal axis of the sound muffler 1 at their endsthat are remote from the waste gas pipes 4, or the prolongations 10, 11.They are provided with a multitude of bores 14,15 which affect to aconsiderable extent the even conveyance of gas and heat because thedischarge cross-section for the waste gases is correspondingly large.

The bulges may be defined in a separate insert member which suitably ismade of two pressed or formed sheet metal halves 16, 17 that are weldedtogether. This is shown particularly in the sections of FIGS. 2 and 3.In FIG. 2 a'section is illustrated at the location of the sound mufflerl where the pipe section 11 of the waste gas pipe 5 enters the insertmember.

It is understood that a corresponding second shell 1' of the muffler isassociated symmetrically with the shell 1 that is drawn in solid lines.For reasons of greater clearness, the shell 1' is only shown in dash anddot lines in FIGS. 2 and 3. While waste gas pipes 2,5 lead to one shellhalf 1 (see also FIG. 1), the other shell half 1 is provided with theexhaust pipes 29 which also are illustrated only in dash and dot linesthrough which the waste gases pass to the exterior.

As reflected by FIG. 3, the sheet metal members 16, 17 that constitutethe insert are placed upon one another with 'their flat sides in such amanner that recesses in them on both sides define bulges 12, 13. Thesheet metal members 16, 17 may be unitarily and materially connectedwith muffler l, for example by welding. Flanges 18, 19 or 20, 21 servefor connecting the waste gas pipes 4 or 5 to two of the four cylindersof the combustion engine. The waste gas pipes 2, 3 are provided withsuitable flanges 22, 23 (FIG. 4).

The size of the bulges 12, 13 is such that the available cross-sectionof the sound muffler 1 is extensively utilized. As a result such anincrease of the cross-section of the waste gas pipes is alreadysufficient for solving the problem on which the invention is based. Inspecial cases, however, more than one increase of the crosssection maybe provided for each prolonged waste gas pipe. In view of the volumeincrease caused by the bulges 12, 13, the prolongations 10, 11 of theexhaust pipes 4, 5 may be made so small that they do not overlap, oronly so little that in practice mutual heating by heat radiation doesnot result.

- The sheet metalmembers 16, 17 separate the space ,27 from space 28which leads to the exhaust pipes partly. Therefore bores 25 may beprovided in thembers 16, 17, as well as perforations 26, as a result ofwhich the waste gases in space27 can reach the space 28 and thereforethe exhaust pipes 29 more easily or quickly.

As shown particularly in FIG. 3, the bulges may have a flattened shapeso that the thickness of the sound muffler need not be enlarged in thatarea.

The sheet metal members l6, 17 as viewed in the longitudinal directionfill the entire cross section of the sound muffler and are welded on tothe sound muffler at their upper and lower longitudinal edges (seeparticularly FIGS. 2 and 3).

avmg now described our invention with reference to the embodimentsillustrated in the drawings, what we desired to protect by letterspatent is set forth in the appended claims.

We claim:

1. Exhaust device for multiple cylinder internal combustion enginescomprising a housing defining an exhaust sound muffler and waste gaspipes, of the type having a waste gas pipe for each cylinder of theassociated engine, said pipes leading separately to the exhaust soundmuffler, the lengths of said pipes between the motor and said mufflerbeing different, while individual waste gas pipes are prolonged by acertain amount inside said muffler, and said waste gas pipes inside saidmuffler having expanded cross-sections.

'2. Exhaust device in accordance with claim 1, where said expandedcross-sections are in the form of bulges.

3. Exhaust device in accordance with claim 1, comprising two prolongedwaste gas pipes extending within said muffler in opposite directionsrelative to the longitudinal axis of said muffler, and where said bulgesextend longitudinally relative to the longitudinal axis of said mufflerand in opposite directions relative to each other.

4. Exhaust device in accordance with claim 3, where said bulges haveequal shapes and are of the same volume.

5. Exhaust device in accordance with claim 4 where apertures are definedin said bulges at the ends remote from said waste gas pipes.

6. Exhaust device in accordance with claim 5, where said parts of saidpipes having said expanded sections are definedby sheet metal havingflat sides disposed upon and connected with one another and havingrecesses defining said bulges.

7. Exhaust device in accordance withclaim 6, where portions of saidparts of sheet metal away from said bulges are provided with aperturesfor the passage of waste gases.

8. Exhaust device in accordance with claim 7 where said bulges presentflat sides.

Patent N5. 5,709,520

Dated January 9, 1975 Inventor(s L I 0 af It is eertified that errorappears in the above-identified patent and that said Letters Patent arehereby con eated as shown below:

Claim 5, line 1 Ghange numeral "1" to 2 Signed and's'ealed this 22nd ofMay 1973,

SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GO TTSCHALK Attesting Officer h ICommissioner of Patents FORM (m'59) uscoMM-Dc scan-ps9 A 1.5. GOVERNMENTPRINTING QFFICE 21969 ()"365'334 UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION- Patent Ne. 520 r I Dated J y Inventor(s) A I Qj S Igr IKg II La, ndgraf It is eertified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Claim 5, line 1 change numeral "1" to --2-'.

Signed andsealed this 22nd of May 1973,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I v ROBERT GOTTSICHALK Attesting OfficerCommissioner of Patents F ORM PO-105O (10-69) USCOMM-DC 60376-P69 U.S.GOVERNMENT PRINTING QFFICE: I959 0-355-334

1. Exhaust device for multiple cylinder internal combustion enginescomprising a housing defining an exhaust sound muffler and waste gaspipes, of the type having a waste gas pipe for each cylinder of theassociated engine, said pipes leading separately to the exhaust soundmuffler, the lengths of said pipes between the motor and said mufflerbeing different, while individual waste gas pipes are prolonged by acertain amount inside said muffler, and said waste gas pipes inside saidmuffler having expanded cross-sections.
 2. Exhaust device in accordancewith claim 1, where said expanded cross-sections are in the form ofbulges.
 3. Exhaust device in accordance with claim 1, comprising twoprolonged waste gas pipes extending within said muffler in oppositedirections relative to the longitudinal axis of said muffler, and wheresaId bulges extend longitudinally relative to the longitudinal axis ofsaid muffler and in opposite directions relative to each other. 4.Exhaust device in accordance with claim 3, where said bulges have equalshapes and are of the same volume.
 5. Exhaust device in accordance withclaim 4 where apertures are defined in said bulges at the ends remotefrom said waste gas pipes.
 6. Exhaust device in accordance with claim 5,where said parts of said pipes having said expanded sections are definedby sheet metal having flat sides disposed upon and connected with oneanother and having recesses defining said bulges.
 7. Exhaust device inaccordance with claim 6, where portions of said parts of sheet metalaway from said bulges are provided with apertures for the passage ofwaste gases.
 8. Exhaust device in accordance with claim 7 where saidbulges present flat sides.